Safety guard for electric switches



5. F. BURCHAM v SAFETY GUARD FOR ELECTRIC SWITCHES Sept. 14., 1926.

Original Filed Dec. 20, 1923 Patented Sept. 14, 1926.

UITE STATES PATENT SAFETY GUARD FOR ELECTRIC SWITCHES.

Application filed December 20, 1923,3eria1 No. 681,772. Renewed .Tune 30, 1926.

This invention relates to improvements in "safety guards for electric switches.

An important object of the invention is to provide a guard or shield which may be at- 5 tached to any type of switch and prevent the hands of the operator from coming in contaict with any part of the conducting materia A further object of the invention is to 1 provide a device of this character which will prevent the hands of the operator from becoming burnt by the sparks which often issue from switches upon closing same.

A further object of the invention is to provide a device of this character which is simple, yet durable, and efficient for the purpose intended.

Other objects and advantages of this invention will be apparent during the course of the following description.

In the accompanying drawing forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a top plan elevation of the device mounted on a conventional type of knife switch,

Figure :2 is a side elevation of the same,

Figure 3 is a top plan elevation of a modified form of the invention, and

Figure 4 is a side elevation of the same.

In the drawing, the Figures 1 and 2 show the preferred embodiment of my invention, the numeral 5 designating the panel board having the sheath bar 6 secured to the lower portion thereof and the pivot bracket 7 mounted on the upper portion. A knife switch comprising blades 8 adapted to swing about a pair of pivot pins 9 and engaging the sheath bar 6 as at 10. A knife bar 11 is secured to the lower portion of the blades 8 and has the usual handle 12 secured thereto by the screw 13. The switch thus described comprises a type commonly used on electric circuits and is known as a knife switch. I provide a guard generally denoted by the numeral 14 and comprising an upper shield 15 which isv adapted to extend over the blades 8, the lower portion being bent at approximately right angles as at 16 and fastened to the knife bar 11 by means of the handle 12, which is firmly secured to the knife bar by the retaining screw 13. The lower portion of the guard 1 1 is bent as at 17 and protects the hands of the operator from flying sparks or the like. The guard 14 is constructed of fibre or other non-conducting material and is mounted to the switch in a manner which will not cause interference with the manipulation thereof.

In the modified form of the invention. illustrated in Figures 3 and A, I show the device in connection with a different form of switch, the type herewith shown being employed for varying the resistance of electric current, being provided with a plurality of contact points 18 which are adapted to engage a similar contact 19 secured to the moving end of a lever 20, said lever being pivoted at its lower extremity by a pivot pin 21, or the like. The guard used on this type of switch, generally denoted by the numeral 23, comprises a comparatively large plate 24 which is secured to the swinging lever 20 by means of a handle 25 which is inserted through an opening formed in the guard 23 and retains the guard firmly thereon. The pla e 2 1 is adapted to cover the contact 19 and extends some distance beyond same,

thereby preventing the hands of the opera-.

tor from coming in contact with any ofthe conducting elements and also eliminating the danger caused by flying sparks. A tongue like extension 26 1s formed on the lower portion of the guard and is adapted to cover the,

lower extremity of the lever 20, thereby eliminating all possibility of the operator receiving injury therefrom.

In. use, the device may be readily mounted upon the conventional types of electric switches without materially altering the construction thereof or interfering with their operation. The device is particularly adapted for switches connected on high voltage lines, due to the greater danger associated with the manipulation thereof and the spar (S which usually issue therefrom. It, is by no means limited to this application however, as it may be advantageously employed on all types of switches which are operated by the laymen with great apprehension,

It is to be understood that the form of my invention herewith shown and described is to be taken as the preferred example of the same, and that various changes in the shape, size, and arrangement'of parts may be resorted to without departing from the spirit or" the invention, or the scope of the subjoined claim.

Having thus described my invention, I claim:

In combination with an electric switch having blades and a handle, a guard comprising a plate having plane opposite .end portions and a plane intermediate said portions disposed at an angle With relation to the end portions whereby the said end portions are offset With relation to each other, the handle of the switch passing through the intermediate portion of the plate and the end portion of the plate being disposed at the opposite sides 01 the blade and the handle and spaced therefrom.

In testimony whereof, I have aflixed my signature.

BENJIMAN F. B'URCHAM. 

